Determination of the Combined Mesio-distal Widths of the Permanent Mandibular Incisors and that of the
Maxillary and Mandibular Canines and Premolars in a Group of Egyptian Children in Suez Governorate:
A Cross-sectional study
Thesis Submitted to
Faculty of Dentistry - Cairo University
In partial fulfillment of the requirements for Master
degree in
Pediatric Dentistry
By
Hagar Mohamed Ahmed Hassan AbozeidB.D.S. Ain Shams University (2010)
Dentist at Badr CityMinistry of Health and Population
Faculty of DentistryCairo University
2018
SUPERVISORS
Ass. Prof. Dr. Manal Ahmed El-SayedAssociate Professor of Pediatric Dentistry and Dental
Public Health, Faculty of Dentistry
Cairo University
Ass. Prof. Dr. Manal Ahmed El-SheikhAssociate Professor of Pediatric Dentistry and Dental
Public Health, Faculty of Dentistry
Cairo University
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The Judgment Committee
Ass. Prof. Dr. Adel Abd El-Azim El-Bardisy
Associate Professor of Pediatric Dentistry and Dental
Public Health, Faculty of Dentistry
Cairo University
Prof. Dr. Nagwa Mohamed AliProfessor of Pediatric Dentistry and Dental Public
Health, Faculty of Dentistry
Menia University
Ass. Prof. Dr. Manal Ahmed El-SayedAssociate Professor of Pediatric Dentistry and Dental
Public Health, Faculty of Dentistry
Cairo University
Ass. Prof. Dr. Manal Ahmed El-SheikhAssociate Professor of Pediatric Dentistry and Dental
Public Health, Faculty of Dentistry
Cairo University
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ABSTRACTDetermination of the Combined Mesiodistal Widths of the
Permanent Mandibular Incisors and that of the Maxillary and Mandibular Canines and Premolars in a Group of Egyptian Children in Suez Governorate:A Cross-sectional study
Hagar Mohamed Abozeid*, Manal Ahmed El-Sayed** and Manal Ahmed El-Sheikh***
Abstract:Background: Tooth size specifically the mesiodistal dimension has an important role in normal occlusion and in arch space analysis as it affects treatment planning and the final results in orthodontic treatment. Tooth size differs among and within populations. It is affected by both genetic and environmental factors.
Objectives: The aim of the current study was to measure the mesiodistal widths of the mandibular incisors, maxillary and mandibular canines and premolars in a group of Egyptian children in Suez Governorate and to correlate between the widths of these teeth to formulate normative data for the Egyptian children.
Materials and Methods: 12-15 year old children (150 boys and 150 girls) from Suez Governorate were included in the present study. The measurements of the mesiodistal widths of the teeth were conducted on dental casts by a digital caliper
Results: The means of the mesiodistal widths of the boys’ teeth were significantly larger than those of the girls. Also, there was no statistically significant difference between the right and left sides in girls. However, in males the right mandibular second premolar was significantly bigger than the left side.
Conclusion: Sexual dimorphism is present between boys and girls where boys had larger teeth than girls. There were no statistically significant differences between the right and left sides in girls. But in boys only the mandibular second premolar showed slight statistically significant difference. The mandibular permanent incisors can be used in the prediction of the mesiodistal widths of the maxillary and mandibular permanent canines and premolars due to positive correlation between them.
* B.D.S Ain Shams University (2010)** Associate Professor of Pediatric Dentistry and Public Health Department, Faculty of Dentistry, Cairo University.** Professor of Pediatric Dentistry and Public Health, Faculty of Dentistry, Cairo University.
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INTRODUCTION
The mesiodistal width of a tooth is defined as the distance between
the two parallel lines, which are perpendicular to the mesiodistal axis of
the tooth tangential to the most mesial and the most distal points of the
crown along a parallel line to the occlusal plane. (Hasegawa, 2014)
Tooth size specifically the mesiodistal dimension has an important
role in normal occlusion and in arch space analysis as it affects treatment
planning and the final results in orthodontic treatment (Memon and
Fida, 2012).
Tooth size differs among and within populations. It is affected by
both genetic and environmental factors. Contributing factors include race,
sex, hereditary, environment, secular changes and bilateral asymmetry.
Environmental factors as nutrition, health conditions and climate affect
the dentition prenatally (Esnaashari et al, 2014).
Malocclusion is a common esthetic and functional problem in the
world. It's a developmental condition caused by alteration in normal
development (Jahan & Hossain, 2011).
The majority of malocclusion, which starts during the mixed
dentition period, can be treated and eliminated in its severity if it was
managed early (Felicio et al, 2010).
Early diagnosis and treatment of malocclusion is important in
orthodontics. For this reason, accurate arch space analysis is needed to
determine the appropriate treatment that may include space maintenance,
space regaining, and guidance of eruption, serial extractions or periodic
check-ups of the patient (Kundi et al, 2012 and Abdelbagi et al, 2016)
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Arch length analysis is the prediction of the meisodistal widths of
the un-erupted permanent canines and premolars to detect the discrepancy
between the available and required spaces. It is of great importance in
determining and handling the developing occlusion of growing children.
Since it will aid in figuring out if the posteriorly available space is
adequate for the good alignment of the permanent teeth or not (Memon et
al, 2012 and Abdelbagi et al, 2016).
Arch space analysis can be done either through:
Radiographs
Prediction tables
Or both (Burhan and Nawaya, 2014).
To this date, few studies on the mesiodistal dimensions of teeth of the Egyptian population were found in the literature. For that reason, this study was carried out as part of a project adopted to gather data from
different Governorates in Egypt on the mesiodistal widths of the permanent mandibular incisors, maxillary and mandibular canines and
premolars. This will help in ra
AIM OF THE STUDY
The aim of the study was to:
I. Determine the combined mesiodistal widths of the permanent
mandibular incisors and that of the maxillary and mandibular right
and left canines and premolars in a group of Egyptian children in
Suez Governorate.
II. Correlate the mesiodistal widths of the permanent mandibular
incisors to that of the maxillary and mandibular right and left
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canines and premolars to formulate normative data for the Egyptian
children.
MATERIALS AND METHODS
As a cross-sectional study was planned, in which multiple regression analyses were performed with 20 independent variables, the expected multiple regression coefficient was estimated to be R=0.50. In this study, 300 subjects needed to be recruited with Probability of Type I Error (α)= 0.05 and power= 90.0% (VanVoorhis et al., 2001). 150 females and 150 males were selected from Nabwia Moussa Preparatory Mixed School in Suez Governorate. The ethical committee in Faculty of Dentistry, Cairo University approved this study. A permission letter that explains the aim of the study was presented to the head of the educational region for his approval to enter the governmental schools. A written consent was given to the school’s principal in charge of the subjects, who were included in the study to sign before the beginning of the procedure.
Inclusion Criteria:
Age: 12-15 years. Full set of permanent dentition from left first permanent molar to right first permanent molar in the upper and lower arch. No apparent orthodontic problem. No previous history of orthodontic treatment. No clinically apparent proximal caries, crown fractures, malformed teeth, interproximal restorations or any dental anomalies. No apparent systemic conditions or genetic syndromes (medically free) that may affect the mesiodistal dimensions of the included teeth.
Exclusion Criteria:
Missing permanent teeth or retained primary ones. Dentition exhibiting morphological anomalies. Crowding, rotation, increased overjet or any other orthodontic condition.Patients were divided into two groups according to gender (150 boys and 150 girls).
Materials:
The materials used were:
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1. Disposable diagnostic sets.2. 150 pairs of perforated stock metal trays size 1*3. Multiple rubber bowls and spatulas.4. Irreversible hydrocolloid impression material**. 5. Hard dental stone***.6. Digital Caliper with a calibrated digital micrometer****, read to the nearest 0.01mm used to measure the tooth size.
*Misr Dental-Egypt**Tropicalgin impression material-Zhermack-Italy***HTM Dent-Turkey****ELORA, Germany
Method:
1. Clinical examination:
A diagnostic chart was made for each student including medical and dental history. Dental examination was made on a student’s bench in the classroom using a disposable diagnostic set that includes a mouth mirror and a probe.
Examination procedures:
A. Impression taking:
Impressions of both the upper and lower arches were taken by fast setting irreversible hydrocolloid impression material (Tropicalgin impression material-Zhermack-Italy) using suitable size perforated study trays. The material was used according to the manufacturer’s instructions regarding mixing and setting time. The impressions were rinsed under running water, wrapped with moist gauze and placed in a polyethylene bag with the student’s name written on the bag until it was poured.
B. Study casts and model trimming:
Each impression was poured within one hour using dental stone to avoid any dimensional changes. The stone was mixed according to the manufacturer’s instructions. The casts were trimmed at Digital Dental Academy laboratory.
C. Measurements taken from the study casts:
Measurements were taken perpendicular to the long axis of the tooth, with a digital caliper entering the interproximal area from the anatomic
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mesial contact point to the anatomic distal contact point of each tooth parallel to the occlusal plane (Priest & Hunter, 1960). All the dimensions were measured directly from the study models using a digital caliper especially designed for dental use.The measurements were recorded in excel sheets to the nearest 0.01mm.The following measurements were recorded from each cast for each student: Mesio-distal width of the four mandibular incisors. Mesio-distal width of the mandibular right canine, first and second premolars. Mesio-distal widths of the mandibular left canine, first and second premolars. Mesio-distal width of the maxillary right canine, first and second premolars. Mesio-distal widths of the maxillary left canine, first and second premolars.
Measuring Device:
According to the manufacturer’s instructions, the digital caliper simplified the reading of the value from the display. The display could be switched from ‘millimeter’ to ‘inches’ and had the function of zeroing the
display at the beginning or anywhere along the slide. The slide of the digital caliper may also be controlled through thumb roller or locked
using a thumbscrew. The readings were displayed to the nearest 0.01mm
REVIEW OF LITERATURE
Teeth development starts in the intrauterine life. Their size is
controlled by hereditary factors and is usually unaffected by external
factors but if subjected to infection, trauma or pathological condition,
hypoplasia or hyperplasia may be expected (Hussein et al, 2009).
Mesiodistal crown diameter, which is also known as tooth size,
tooth crown size or tooth width in human populations is an important
focus in many studies as it can be used in forensic investigations, human
evolution, biological issues and clinical dentistry. In clinical dentistry, the
relationship between the mesiodistal crown diameter and arch alignment
is important to determine malocclusion and crowding as a correct
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mesiodistal crown diameter relationship between the upper and lower
teeth is essential for proper inter-digitation, over-jet and overbite in final
orthodontic treatment (Hattab, 2013).
Tooth size implies to the mesio-distal widths of the upper and
lower teeth. Certain relationships should be present between the
dimensions of the upper and lower teeth to provide adequate inter-
digitation, overbite and over-jet (Batool et al, 2008).
Tooth size discrepancy is the disproportion in the sizes of the teeth.
It’s usually limited to a single tooth such as peg lateral incisor (Batool et
al, 2008).
Moorres and Reed (1954) proposed the most commonly used
method for tooth size determination. Mesiodistal tooth size is defined as
‘the greatest distance between the contact points of the proximal surfaces
of the dental crown, with the calipers parallel to both the occlusal and
vestibular surfaces.
The mesiodistal dimension of the permanent teeth is essential in
orthodontic diagnosis and treatment planning, and its also considered as an
important aspect in space analysis, treatment planning and orthodontic
treatment to reach normal occlusion (Hashim et al, 2005 and Al-Janabi,
2005).
The mesiodistal dimensions of both the upper and lower teeth
should be in appropriate balance as they greatly affect posterior inter-
digitation, overbite and over-jet in centric occlusion. The mesiodistal
dimension should also be in balance with the arch size for appropriate
alignment (Hashim and Al-Ghamdi, 2005).
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Comprehensive orthodontic treatment’s essential purpose is to
achieve ideal occlusion, overbite and over-jet where tooth size
discrepancies of the maxillary and mandibular arches play a crucial role.
It’s hardly possible to reach ideal occlusion if there is tooth size
discrepancy (Lopatiene et al, 2009).
For the orthodontist to determine functional and esthetic results of
cases, the determination of tooth size discrepancies is an essential
diagnostic tool (Hashim and Al-Ghamdi, 2005).
The size of the permanent teeth can’t be estimated on the basis of
the size of the primary teeth as their sizes are inherited separately
(Janosevic et al, 2006).
Tooth size and shape varies from one person to another, from
males and females and from one ethnic group to the other depending on
genetic factors (Moon et al, 2006).
Sexual dimorphism:
Sexual dimorphism is the differences in the size or shape of teeth
between males and females of the same species (Bunger et al, 2014).
Environment and genetics both affect tooth size and it’s strongly
linked to sex and ethnicity. Males’ teeth are larger in size than those of the
females and Africans have larger teeth than Europeans (Altherr et al, 2007).
Sexual dimorphism in different races:
China:
In a study of four hundred and fifty nine subjects (295 males and
164 females), the mesiodistal crown dimensions of all erupted permanent
incisors, canines and premolars were measured using a digital caliper. It
was concluded that sexual dimorphism existed between Southern
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Chinese males and females in incisors, canines and premolars and new
linear regression equations were formulated (Ling and Wong, 2006).
Turkey:
In a study of four hundred and fifty dental casts with mean age
15.25-+ 1.25 that were chosen from the records of the patients at the
Department of Orthodontics of Selcuk University, Faculty of Dentistry,
Konya, Turkey to formulate new regression equations for the mixed
dentition analysis. It was found out that males had larger teeth than
females. There was no significant difference between the right and left
sides. Both Moyers and Tanaka and Johnstons’ analyses can’t be applied
on the Turkish population and new equations were formulated (Uysal et
al, 2009).
Yemen:
A sample of one hundred and seventy six subjects (82 males and 94 females) with an age range (13-25) was used to study the mean mesiodistal widths and possible sex differences among Yemeni
population. The sample selected had different types of malocclusions (94 Angle Class I, 37 Class II division 1, 36 Class II division 2 and 9 Class
III). The mesiodistal widths were measured using digital caliper on
dental casts. The results showed that males had significantly larger teeth
than females and also there were no significant differences in the
mesiodistal teeth widths between the right and left sides (Al-Gunaid et
al, 2012).
Malocclusion:
It is a considerable deviation from the ideal occlusion caused by
differences in the size and location of the teeth and their arches and also
the facial bones and soft tissues. Malocclusion isn’t a healthy or a disease
condition (Hassan and Rahimah, 2007).
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Malocclusion may be represented as either:
Mal-alignment in the same arch: of a tooth or more in the same
arch. The tooth may show rotation, tipping, displacement, infra-
occlusion, supra-occlusion or transposition.
Mal-relationship of the dental arches: in relation to normal
occlusion. Its may happen in any of the three planes: antero-
posterior, vertical or transverse (Hassan and Rahimah, 2007).
Malocclusion, a developmental condition, is one of the common
esthetic and functional problems present. Malocclusion results from
distortion of normal development (Jahan and Hossain, 2011).
It mostly occurs due to imbalance between the size of erupting
permanent teeth and the available space in the arch (Adnani et al, 2011).
It is also defined as any variation from normal occlusion, which is
mainly due to the difference between the size of teeth and the size of their
arches (Butt et al, 2012).
Tooth size differences in different races:
A study was carried out to compare the mesiodistal crown
dimensions in three populations from Egypt, Mexico and United States.
The sample consisted of 54 Egyptian subjects (30 males and 24 females),
57 subjects (35 males and 22 females) from Iowa, United States and 60
subjects (26 males and 34 females) from
Mexico. All subjects had normal class I occlusion with no history
of orthodontic treatment. The results showed that there was a
difference in the mesiodistal dimensions between the three
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populations. Also, there was sexual dimorphism where males had
larger teeth than females among each population especially in the
canines and premolars and finally there was no statistical
significance between the right and left sides for all populations
(Bishara et al., 1989).
Fifty four Dominican American orthodontic patients (36 men and
18 women) were chosen to conduct a study to form normative data
of the mesiodistal dimensions of the permanent dentition in the
Dominican Republic and to compare the results obtained with those
of previous studies and also compare it with similar studies
obtained on African American and North American white
populations. It was concluded that sexual dimorphism exist. In
addition, the data were similar to those of previous study and that
the data for the Dominican American are close to those of the
African Americans and smaller than that of the North Americans
(Santoro et al, 2000).
In another study that was carried out by measuring the mesiodistal
widths of the teeth of Caucasian, African, Japanese individuals with
Brazilian ancestry on dental casts using a digital caliper and
compared with each other. The sample consisted of 30 Caucasian
individuals, 40 Africans, and 30 Japanese with mean age 15-16
years old. All subjects showed normal occlusion and not previous
orthodontic treatment. It was concluded that Africans had larger
mesiodistal widths followed by the Japanese and then the
Caucasians (Fernandes et al, 2013).
Arch length analysis in different countries:
Saudi Arabia:
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Al-Khadra study was used to study the prediction of the
mesiodistal width of the un-erupted canines and premolars in Saudi
population. He concluded that 35% confidence level in Moyers analysis
was more precise than the 75% confidence level and that Tanaka and
Johnston equations over-estimated the size of the buccal part in Saudi
people. So further studies were needed to formulate new equations and
compare results with other studies.
Another study was carried out where dental casts of sixty-five
subjects (37 males and 28 females) were collected to predict the size of
the un-erupted canines and premolars in Saudi population. Using an
electronic digital caliber to measure the mesiodistal widths of teeth of
both arches from the left first permanent molar to the right first
permanent molar. It was concluded that, when both sexes combined the
50% confidence level of the canines and premolars is more precise. This
differs from Al-Khadra conclusion because he didn't take into
Jordan:
The reliability of both Moyers and Tanaka and Johnston’s analyses
were investigated in Jordanian population. A sample of one hundred and
thirty males and sixty-five females between the ages of 14 – 16 years was
collected. The mesiodistal widths of the lower permanent incisors and the
maxillary and mandibular canines and premolars were measured using a
digital vernier caliper. It was found out that there is a difference between
the sum of the mesiodistal widths of the canines and premolars between
males and females. It was also found out that Moyers analysis could be
used at probability levels 65% and 75% for Jordanian population. Tanaka
and Johnston’s equations aren’t precise and can’t be used for the
Jordanian population. New regression equations were formulated. (Abu
AlHaija and Qudeimat, 2006)
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Syria:
A study of six hundred and seventy sets of dental casts (342
females and 328 males) was performed to determine the applicability of
both Moyer’s and Tanaka and Johnston analyses in Syrian population.
The measurements were made using an electronic digital caliper. It was
found out that Moyer’s analysis was more accurate for Syrian
population but the correct percentile should be used according to gender
because at the 50% percentile levels, it underestimated the actual values
in males but were comparable with that of the females. While in the 75%
percentile levels it overestimated the actual values in the females but was
comparable with the males. In Tanaka and Johnston’s equations, new
equations were formulated. (Burhan and Nawaya, 2014)
SUMMARY
This study was conducted to measure the mesio-distal widths of the
mandibular incisors, maxillary and mandibular canines and premolars in a
group of Egyptian children in Suez Governorate and to correlate between
the widths of these teeth to formulate normative data for the Egyptian
population.
The sample included 300 students (150 males and 150 females) in
the age range of 12 to 15 years from Nabwia Moussa mixed preparatory
school in Suez Governorate.
The measurements of the mesio-distal widths of the teeth were
done on dental casts by a digital caliper, which was held perpendicular to
the long axis of the tooth, after taking alginate impressions of the upper
and lower arches and pouring dental casts using dental stone.
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The results of this study showed that; the means of the mesio-distal
widths of the boys’ teeth were significantly larger than those of the girls.
Also, there was no statistically significant difference between the right
and left sides in girls. However, in males the mandibular second premolar
showed statistically significant difference between the right and left sides.
There was positive significant correlation between the mesiodistal
widths of upper right canine and premolars & the mesiodistal widths of
the lower incisors in both boys and girls. Futhermore, there was positive
significant correlation between the mesiodistal widths of upper left canine
and premolars & the mesiodistal widths of the lower incisors in both boys
and girls.
It was also concluded that there was positive significant correlation
between the mesiodistal widths of upper right canine and premolars & the
mesiodistal widths of the upper left canine and premolars in both boys
and girls. There was also a positive significant correlation between the
mesiodistal widths of lower right canine and premolars & the mesiodistal
widths of the lower left canine and premolars in both boys and girls.
And finally, the results showed that there was positive significant
correlation between the mesiodistal widths of lower left canine and
premolars & the mesiodistal widths of the lower incisors in both boys and
girls. Besides, there was positive significant correlation the mesiodistal
widths of lower right canine and premolars & the mesiodistal widths of
the lower incisors in both boys and girls.
CONCLUSIONS
Based on the results of this study the following was concluded:
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1. The presence of sexual dimorphism between boys and girls where
boys had larger teeth than girls.
2. No statistically significant differences between the right and left
sides in girls so clinicians can rely on the mesiodistal teeth widths
of one side if the other side is missing.
3. No statistically significant differences between the right and left
sides in boys except for the mandibular second premolar.
4. Positive significant correlation is present between the mesiodistal
widths of the mandibular permanent incisors and the mesiodistal
widths of the maxillary and mandibular permanent canines and
premolars, which allows the mandibular permanent incisors to be
used in their prediction.
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